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package com.lcfgly.util;

import java.io.Serializable;
import java.security.MessageDigest;

/**
 *
 * @author lcfgly
 */
public class Encode  implements Serializable  {
    /**
     * MD5
     * @param s
     * @return 
     */
    public final static String MD5(String s)
    {
        char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
        try {
            byte[] strTemp = s.getBytes();
            MessageDigest mdTemp = MessageDigest.getInstance("MD5");
            mdTemp.update(strTemp);
            byte[] md = mdTemp.digest();
            int j = md.length;
            char str[] = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++)
            {
                byte byte0 = md[i];
                str[k++] = hexDigits[byte0 >>> 4 & 0xf];
                str[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(str);
        }catch (Exception e){
            return null;
        }
    }
    
    /**
     * 获取随机字符串
     * @param n
     * @return 
     */
    public final static String randomString(int n)
    {
        String result="";
        if(n <= 0)
            return result;
        char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f','g','h','i','j','k','l','n','m','o','p','q','r','s','t','u','v','w','x','y','z',
            'A','B','C','D','E','F','G','H','I','J','K','L','N','M','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
        for(int i=0;i<n;i++)
        {
            int j=(int)(Math.random()*55);
            try{
                result+=hexDigits[j];
            }catch(Exception e){
                e.getMessage();
                result+="l";
            }
        }
        return result;
    }
    
    /**
     * 密码加密
     * @param password
     * @param str
     * @return 
     */
    public final static String passwordcode(String password,String str){
        password=MD5(password);
        return password=MD5(password+str);
//        return password.substring(5, 25);
    }
    
}
